As the USS Enterprise-D picked up the mission where Galen left off, this ship shadowed the Enterprise, eventually arriving at Vilmor II, where the captain and a few of his crew surprised the Cardassian, Klingon, and Federation delegations that were present there, as they were attempting to discover the secret of the genetic codes that led them to the planet.

The flagship was identified as being the D'ridthau (β) in an early draft of "What You Leave Behind". Later revisions removed the name from the script and the name survived only in the pronunciation guide of the episode. However, in the novelization of the episode, the name of the flagship was retained and mentioned by AdmiralRoss. The D'ridthau may have been of the D'deridex-class, which was the only Romulan starship class visible, or an entirely unknown class altogether.

Twenty years later, one of these ships was captured, and contained the logs that provided new information to the Klingon High Command on the Khitomer attack. These logs, according to Data, "clearly indicate a transmission from the outpost to the Romulans moments before the shields dropped." The High Command had learned of the treachery, but according to K'mpec, "only the council knew whose security code had been transmitted. Ja'rod, father of Duras."

Since the House of Duras was powerful, according to K'mpec, "if the truth were known, it would shatter the council, almost certainly plunge us into civil war." Because "someone had to be blamed," the Council revealed that Mogh was responsible for the treason, and since Worf was in Starfleet, they "did not expect [him] to challenge the judgment." (TNG: "Sins of the Father")